With ever increasing health care costs, hand-held or otherwise portable test kits, typically either wholly disposable or with disposable parts, have become a popular, low-cost alternative to expensive visits to a specialized health care provider and/or time consuming laboratory testing. Tests related to conditions such as pregnancy, fertility, and diabetes (to name only a few), may be quickly and accurately performed in home. Test devices may also be used at a point of care (e.g., lab bench readers) to provide quick results. The test devices may also be used in the field such as in remote areas where the time to take a sample and have it delivered for testing may make accurate testing impractical and/or expensive. For example, a camper may have little time to assess the severity of a hiking companion's wound. A myotoxin or aflatoxin test device may be carried in a backpack and used to quickly determine whether immediate assistance is needed (e.g., venomous snake bite), or a more measured response is called for (e.g., standard first aid). Useful test devices such as these are not limited to health condition testing. Test devices for environmental conditions such as mold, toxins, bacterial contamination or other types of pests may be implemented for field use.
Test devices of this nature may collect and/or generate a variety of different types of data. In many cases, LEDs or other light sources internal to the devices illuminate samples of interest and/or regions where chemical reactions occur, and the absorbance, reflectivity, fluorescence, or other optical characteristic of the sample and/or region is detected with photodiodes, CCD arrays, or other light sensors. The output of the sensors is typically indicative of the presence and/or amount of a substance in a sample. Although optical interrogation techniques are common, other detection methods that sense current or impedance are also sometimes used. The results obtained when the test is used are often displayed to the user as an output in the form of illuminated LEDs or a small LCD display screen. Expanding the usefulness of these devices, especially with minimal cost increases, is desirable.